Nothing to worry about. These are "shadow" references for the USA airlines, who are on a different GDS system. Quite normal, sometimes they are visible, sometime they are not. If you go to the seat selection area (after ticketing if you don't have status) you will see the PNR / locator for US and AA, you can then go to AA.com and muck around with seating and BAEC numbers. Less reliably, the same for US Airways website.

Hopefully you don't make too many changes to the above, otherwise they multiply like that Walt Disney cartoon!